PenaltySP FE


# PenaltySP_FE

#include <analysis/fe_ele/penalty/PenaltySP_FE.h>

class PenaltySP_FE: public FE_Element ;

FE_Element


PenaltySP_FE is a subclass of FE_Element used to enforce a single point constraint. It does this by adding \(\alpha\) to the tangent and \(\alpha * (U\_s - U\_t)\) to the residual at the locations corresponding to the constrained degree-of-freedom specified by the SP_Constraint, where \(U_s\) is the specified value of the constraint and \(U_t\) the current trial displacement at the node corresponding to the constraint.

// Constructor


// Destructor


// Public Methods




To construct a PenaltySP_FE element to enforce the constraint specified by the SP_Constraint theSP using a value for \(\alpha\) of alpha (which, if none is specified, defaults to \(1.0e8\)). The FE_Element class constructor is called with the integers \(1\) and \(1\). A Matrix and a Vector object of order \(1\) are created to return the tangent and residual contributions, with the tangent entry being set at \(\alpha\). A link to the Node in the Domain corresponding to the SP_Constraint is also set. A warning message is printed and program terminates if there is not enough memory or no Node associated with the SP_Constraint exists in the Domain.


Invokes the destructor on the Matrix and Vector objects created in the constructor.


Causes the PenaltySP_FE to determine the mapping between it’s equation numbers and the degrees-of-freedom. From the Node object link, created in the constructor, the DOF_group corresponding to the Node associated with the constraint is determined. From this DOF_Group object the mapping for the constrained degree of freedom is determined and the ID in the base class is set. Returns \(0\) if successful. Prints a warning message and returns a negative number if an error occurs: \(-2\) if the Node has no associated DOF_Group, \(-3\) if the constrained DOF specified is invalid for this Node and \(-4\) if the ID in the DOF_Group is too small for the Node.

Returns the tangent Matrix created in the constructor.

Sets the FE_Elements contribution to the residual to be \(\alpha * (U_s - U_t)\), where \(U_s\) is the specified value of the constraint and \(U_t\) the current trial displacement at the node corresponding to constrained degree-of-freedom. Prints a warning message and sets this contribution to \(0\) if the specified constrained degree-of-freedom is invalid. Returns this residual Vector set.

virtual const Vector &getTangForce(const Vector &disp, double fact = 1.0);
Sets the FE_Elements contribution to the residual to be \(\alpha * (U\_s - disp\_t)\), where \(U\_s\) is the specified value of the constraint and \(disp\_t\) the value in disp corresponding to constrained degree-of-freedom. Prints a warning message and sets this contribution to \(0\) if the mapping, determined in setID(), for the the specified constrained degree-of-freedom lies outside disp.

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